Technical Field
The present invention relates to a wireless communication device and a wireless communication system using a directional antenna, and more particularly, a wireless communication device and a wireless communication system, which are capable of reducing a maintenance load, predicting the occurrence of a communication failure with a high degree of accuracy, and thus improving reliability of communication.
Related Art
In the past, as a fixed wireless access (FWA) wireless communication system having quasi-millimeter to millimeter wavebands, there is a system in which point-to-point (P2P) wireless communication is performed between specific fixed communication devices using an antenna having sharp directivity. Antennas of communication devices constituting a pair are installed to face each other.
In this wireless communication system, when deviation in an antenna direction occurs or a building is newly installed between two points, a wireless signal is “unlikely” to arrive linearly (with no reflection), and there is a risk that a communication failure will occur. If it is possible to detect a possibility of a communication failure in advance, a countermeasure of relocating a base station can be taken, and thus a technique of predicting the occurrence of a communication failure through image analysis has been developed.
For example, a technique in which an imaging device that photographs a counterpart communication device is installed in a communication device, and a user sequentially checks photographed images and detects an abnormality or a technique of calculating a luminance difference in a direction between frames of an image and activating an alert when a luminance difference is large has been developed.
However, it is very complicated and large in a work load for a maintenance person to check all photographed images, and in the alert activation based on a comparison of a luminance difference, it responds even to events which are not related to a communication failure such as the weather or a sunshine condition, and an alert is often erroneously activated.
The technique of predicting the occurrence of a communication failure based on an image is disclosed, for example, WO/2013/125265, entitled “Radio Communication Apparatus, Radio communication method, and Radio Communication System” (Hitachi Kokusai Electric Inc.). In the technique disclosed in WO/2013/125265, an imaging unit whose optical axis is oriented in the same direction as a main lobe direction of a directional antenna is arranged, a reference image indicating the likelihood for an opposite wireless communication device is photographed and stored as reference image data, photographed image data photographed at regular intervals is compared with the reference image data to detect whether or not an obstacle is oriented in a radio wave direction, and a notification of a detection result is given.